|Pilot Radio and Tube Corporation Super WASP K-110 Receiver|
Pilot Radio and Tube Corporation
|Model||Super WASP K-110|
|Description||Double Duty Receiver for long and short waves|
HEN the original Wasp receiver was being designed, the question arose as to whether wc thonld merely add an audio amplifier or at once attempt a stage of radio-frequency amplification. Even a very brief analysis showed that it would be wise to defer the R.F. stage until several questions could be answered in better form than that represented by the short-wav« tuners on the market. The Wasp therefore appeared with an audio amplifier, and it was exceedingly well received by short-wave broadcast listeners. Having found the Wasp to be entirely satisfactory in the field as well as in the laboratory, we were encouraged to proceed with the original purpose of nsing a stage of tuned R.F. This has been done in the Super-Wasp, to the final form of which the entire Pilot staff has contributed in one manner or another. A considerable portion of the work was done simultaneously in New York, by John Geloso and Robert Hertzberg, and at the writer's home.in West Hartford, Conn,, so that independent information might be used to disclose any of those errors which happen too often when all work together at one place and become victims of an opinion. The Super-Wasp as it now stands is unquestionably the best allround short-wave receiver ever offered the listener. Its points of superiority are as follows: (1) Increased sensitivity and selectivity made possible by the TUNED screen-grid R.F. stage. (2) Universal wavelength range. Tones from 14 to 500 meters. An excellent broadcast receiver as well as tbe finest of all short-wave sets. (3) Absolutely no "hand capacity" effects. (4) Completely shielded. (5) Easily assembled and wired from kit of parts. (6) Inexpensive. And last, bat most important, (7) Ability to bring in short-wave broadcasting stations better than all previous short-wive receiver!. Builda Super-Wasp and experience tbe greatest of all radio thrills—hearing foreign broadcasting stations. The editor of RADIO DESIGN, while testing a Soper-Wasp for a few minutes after dinner and then again before going to bed (location: New York), beard stations in Chelmsford, England; Manitoba, Canada; and Costa Rica, Central America! These were broadcasting voice and music, NOT CODE. Beginning with the matter of shielding, one had at once the question of the material to be used and the thickness required. Aluminum has some evident advantages in that it does sot tarnish readily, may be formed easily and is light. It was therefore used and a light gauge made possible by placing tbe R.F. shield and the detector shield at opposite ends of the set. The baseplate or “snb-panel" of tbe set was made of much heavier sheet aluminum so as to provide a zero-potential plane which would not be upset by currents flowing in it. For the same reason also the panel was made of heavier material. There is not space here to discuss the reasons which led to the particular location of the wiring, the use of a ground at each socket, the series feed of the 222 plate supply through the tuned detector-feed circuit, or the rather unusual circuit arrangement inside the cans. We can say only that the R.F, amplification obtained has been so adjusted that it produces a very handsome improvement in performance (as compared with the Wasp) while at the same time assuring a gratifying freedom from "crankiness". Since the set is to be used with all sorts of antennas this obviously means that the R.F. gain cannot be pushed to extremes. For this so apology is offered. On the contrary, I wish to assert that any materially greater gain would be worse than useless since the “useful selectivity'1' of the set would be ruined thereby, besides creating operating difficulties in the way of uncontrolled oscillation when the set is worked under improper conditions. The practical set for sale in kit form ir the on« which works when correctly assembled—not the one which works if everything is exactly and critically adjusted. floD BROADCAST RECEPTION ON SUPER-WASP In the broadcast region the Super-Wasp can be thought of as comparing very nicely indeed with other four and five-tube sets. Obviously one must not expect the same selectivity from two tuned circuits as from three or four, nor will a single 222 develop the same gain as a number of the same. It is therefore not pretended that seven-tube performance has been obtained. None the less, both the sensitivity and the selectivity are such as to permit good use of the set to be made in tbe normal broadcast band whenever the short waves are behaving badly. Similarly, when the normal receiver is struck by a "dead evening", the Super-Wasp need bat be shifted to the short waves. Tbe first model Super-Wasp had been provided with R.F, coils carrying primaries, also providing for condenser feed from the antenna to the top (grid) end of the tuned circuit. This was tbr same arrangement that had been used in the original Wasp receiver. It was found that tbe condenser feed was not well suited for use in the broadcast region of 200-500 meters for the reason that satisfactory coupling could not be obtained unless the feed condenser was enlarged materially. When this was done the condenser was of a capacity which tuned the antenna as a series system and produced a condition of two-frequency response—a wholly inoperative condition.
These manuals are available for the above equipment:
|Pilot Radio and Tube Corporation -- Super WASP K-110 -- User Manual|
|Manual Type||User Manual|
|Size||580.12 Kbytes (594038 Bytes)|
|Quality||Scanned document, reading partly badly, partly not readable.|
|Upload date||27 September 2015|
|Downloads||88 since 27 September 2015|
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